Large-scale development of a WLAN makes a smart WLAN terminal with mobility and portability more and more popular. However, a WLAN module in a smart WLAN terminal is power-consuming, and a user has to disable the WLAN module for long to save power.
At present, in order to keep a WLAN terminal always online to develop more services, an 802.11 standard defines a Power Save (PS) function. FIG. 1 is a flowchart of PS according to an 802.11 standard, and as shown in FIG. 1, the PS flow includes the following steps.
Step 101: a WLAN terminal is associated with an Access Point (AP) to obtain an Internet Protocol (IP) address.
Here, the WLAN terminal is associated with the AP for identity authentication through a WLAN interface, the WLAN terminal obtains the IP address from the AP after passing the identity authentication, and then the WLAN terminal performs data communication with a network.
Step 102: the WLAN terminal notifies the AP that the WLAN terminal is about to enter a PS state.
Here, before entering the PS state, the WLAN terminal may send a notice to the AP to notify the AP that the WLAN terminal is about to enter the PS state.
Step 103: the AP caches data sent by another data source to the WLAN terminal.
Here, the AP may cache the data sent by the other data source to the WLAN terminal after receiving the notice from the WLAN terminal in Step 102.
Step 104: the WLAN terminal enters the PS state.
After Step 102, the WLAN terminal disables a wireless transceiver to enter the PS state.
Specifically, a WLAN module of the WLAN terminal enters a sleep state, at which moment the WLAN terminal does not receive or send any data.
Step 105: the WLAN terminal quits the PS state.
Specifically, the WLAN terminal enables the wireless transceiver to quit the PS state, that is: the WLAN module of the WLAN terminal enters an active state, and the WLAN terminal performs normal data communication with the network.
Step 106: the WLAN terminal notifies the AP that it quits the PS state.
Step 107: the AP transmits the cached data to the WLAN terminal.
Specifically, the AP transmits the data cached when the WLAN terminal in the PS state to the WLAN terminal after receiving the notification from the WLAN terminal that the WLAN terminal quits the PS state, and then the WLAN terminal performs normal data communication with the network.
From the abovementioned flow, the PS flow in the existing 802.11 standard at least has the following problems:
1) the WLAN terminal is needed to frequently disable and enable the wireless transceiver to save power, and since disabling and enabling of the wireless transceiver cannot be automatically controlled by a network side, a service involving data transmission, such as an instant message and an advertisement, cannot be implemented, which greatly limits a network function;
2) the AP caches the data sent by other data sources when the WLAN terminal is in a sleep state, but for an AP focusing on wireless access, its processing capability and storage space are both limited, and cannot cache bulk data, and moreover, when multiple WLAN terminals enter the PS state, the AP may keep discarding data of the WLAN terminals due to limited processing capabilities and storage spaces, which may cause multiple retransmissions of a service message and frequent retransmissions for a lost packet, reduce network efficiency and lower a user experience greatly; and therefore, the method cannot meet the requirement on bulk data caching.